This study involves an investigation into the molecular mechanism of energy transduction in biological membranes. The mechanism of the coupling or oxidative energy to active transport and phosphorylation is being pursued through a study of mutants of Escherichia coli and through a disassembly and reassembly of the components of the various systems. The energetics of individual transport systems, the study of mutant Mg2 ion-ATPases, and the structure and function of the components of the ATP synthetase complex are under investigation. BIBLIOGRAPHIC REFERENCES: Tsuchiya, T. and Rosen, B.P., Restoration of Active Calcium Transport in Vesicles of and Mg2 ion-ATPase Mutant of Escherichia coli by Wild-Type Mg2 ion-ATPase. Biochem. Biophys. Res. Commun. 63, 832-838 (1975). Rosen, B.P. and Adler, L.W., The Maintenance of the Energized Membrane State and Its Relation to Active Transport in Escherichi coli. Biochem. Biophys. Acta 387, 23-26 (1975).